Analysis of control process structure on information systems project performance.

A study into the extent to which IT departments in top performing local companies decentralise and standardise their project methods and performance criteria controls, taking into consideration software process predictability. In addition the overall interactive effects, among the independent variables as cited, on project performance is analysed

Knee extension range of motion and self-report physical function in total knee arthroplasty: mediating effects of knee extensor strength

Abstract Background Knee extensor strength and knee extension range of motion (ROM) are important predictors of physical function in patients with a total knee arthroplasty (TKA). However, the relationship between the two knee measures remains unclear. The purpose of this study was to examine whether changes in knee extensor strength mediate the association between changes in knee extension ROM and self-report physical function. Methods Data from 441 patients with a TKA were collected preoperatively and 6 months postoperatively. Self-report measure of physical function was assessed by the Short Form 36 (SF-36) questionnaire. Knee extensor strength was measured by handheld dynamometry and knee extension ROM by goniometry. A bootstrapped cross product of coefficients approach was used to evaluate mediation effects. Results Mediation analyses, adjusted for clinicodemographic measures, revealed that the association between changes in knee extension ROM and SF-36 physical function was mediated by changes in knee extensor strength. Conclusions In patients with TKA, knee extensor strength mediated the influence of knee extension ROM on physical function. These results suggest that interventions to improve the range of knee extension may be useful in improving knee extensor performance.</p

Development of a prediction model to estimate the risk of walking limitations in patients with total knee arthroplasty

Objective: Early and accurate risk prediction of walking limitations after total knee arthroplasty (TKA) is important for clinical and economic reasons. However, to our knowledge, no studies have systematically integrated multiple predictors into a single, clinically practical model. Our study aimed to develop a prediction model to estimate the risk of post-TKA walking limitations. Methods: We performed a prospective cohort study of 1096 patients who underwent elective, primary TKA between July 2013 and September 2014. Candidate predictors included patient demographics, surgical factors, and pre- and early (1-mo) post-TKA functional measures. The outcome of interest was self-reported walking limitations at 6 months of post-TKA. We used multivariable proportional odds regression with bootstrap internal validation to develop the model. Results: In all, 12% of patients reported walking limitations (maximum walk time ≤ 15 min) at 6 months postsurgery. The main predictors of increasing levels of walking limitations were preoperative walking limitations (overall p < 0.001), higher levels of body mass index [interquartile range (IQR)-OR 1.3, 95% CI 1.2–1.5], lower values of 1-month post-TKA gait speed (IQR-OR 1.9, 95% CI 1.3–2.6), the presence of contralateral knee pain (OR 1.9, 95% CI 1.2–3.0), and the use of a quadstick preoperatively (OR 3.5, 95% CI 1.7–7.3). The prediction model had an optimism-corrected concordance index of 0.71. Conclusion: A small but sizable proportion of patients with TKA had persistent mobility limitations. Our prediction model may help to risk-stratify patients, and external validation is required before the model can be used in clinical practice

Development of a Prediction Model to Estimate the Risk of Walking Limitations in Patients with Total Knee Arthroplasty

Objective. Early and accurate risk prediction of walking limitations after total knee arthroplasty (TKA) is important for clinical and economic reasons. However, to our knowledge, no studies have systematically integrated multiple predictors into a single, clinically practical model. Our study aimed to develop a prediction model to estimate the risk of post-TKA walking limitations. Methods.We performed a prospective cohort study of 1096 patients who underwent elective, primary TKA between July 2013 and September 2014. Candidate predictors included patient demographics, surgical factors, and pre-and early (1-mo) post-TKA functional measures. The outcome of interest was self-reported walking limitations at 6 months of post-TKA. We used multivariable proportional odds regression with bootstrap internal validation to develop the model. Results. In all, 12% of patients reported walking limitations (maximum walk time ? 15 min) at 6 months postsurgery. The main predictors of increasing levels of walking limitations were preoperative walking limitations (overall p < 0.001), higher levels of body mass index [interquartile range (IQR)-OR 1.3, 95% CI 1.2-1.5], lower values of 1-month post-TKA gait speed (IQR-OR 1.9, 95% CI 1.3-2.6), the presence of contralateral knee pain (OR 1.9, 95% CI 1.2-3.0), and the use of a quadstick preoperatively (OR 3.5, 95% CI 1.7-7.3). The prediction model had an optimism-corrected concordance index of 0.71. Conclusion. A small but sizable proportion of patients with TKA had persistent mobility limitations. Our prediction model may help to risk-stratify patients, and external validation is required before the model can be used in clinical practice. The Journal of Rheumatology. © Copyright 2016. All rights reserved

Are patients more satisfied and have better functional outcome after bilateral total knee arthroplasty as compared to total hip arthroplasty and unilateral total knee arthroplasty surgery? A two-year follow-up study

This study aims to review the quality of life and physical improvement achieved by total joint arthroplasty surgeries, namely unilateral TKA, bilateral TKA and THA. We hypothesize that patients who undergo bilateral TKA should have greater improvement in patient-reported outcome measures, as compared to patients who had unilateral TKA, and their outcomes may be comparable to that of THA. We analyzed prospectively collected data of all patients who underwent unilateral TKA, bilateral TKA and THA (5291, 187 and 529 patients respectively) for end-stage osteoarthritis at a tertiary hospital during the 5-year period. Patients who underwent bilateral TKA had a greater degree of improvement in SF-36, Knee Society Score – Scores as compared to unilateral TKA at 6 months and 2 years follow-up. Bilateral TKA had the highest proportion of patients who were satisfied and had expectations met by surgery

Quality of Life, Outcome Scores, and Prognostic Factors of Persistent Fixed Flexion Deformity at Six Months after Total Knee Arthroplasty

This study examined quality of life (SF-36), Clinical Knee Society (Function/Knee) score and Oxford Knee score of primary total knee arthroplasty (TKA) patients with persistent fixed flexion deformity (FFD) ≥10° at six months follow-up. Pre-operative and post-operative clinical data of Group 1 (n=95; 0°10°) and Control (n=209; FFD=0°) were analysed. FFD improvement was maintained in Control and Group 1 at two years while Group 2 demonstrated little change. Flexion decreased at six months before improving at two years post-TKA was noted in all groups. For Control, significant improvements in majority of SF-36's domains except general health were observed. For Groups 1 and 2, significant improvements were observed in SF-36's physical role, physical role functioning, bodily pain, and social role functioning. Vitality improvement was indicated in Group 1 while emotional role functioning was observed in Group 2. Significant improvements in Clinical Knee Society and Oxford Knee scores were also observed in all groups. Multiple regression analysis revealed that pre-operative factors such as gender ( p =0.035) and pre-operative FFD ( p =0.002) were predictors that correlated with FFD improvement. Our results suggested that FFD have significant impact on quality of life and outcome scores and whenever possible, these should be tracked in order to obtain sufficient information for understanding and aiding the recovery of residual FFD patients after TKA

Predicting individual knee range of motion, knee pain, and walking limitation outcomes following total knee arthroplasty

Background and purpose — Up to 20% of patients are dissatisfied after total knee arthroplasty (TKA), mainly because of pain and restricted physical function. We developed a prediction model for 6-month knee range of motion, knee pain, and walking limitations in patients undergoing TKA surgery. Patients and methods — We performed a prospective cohort study of 4,026 patients who underwent elective, primary TKA between July 2013 and July 2017. Candidate predictors included demographic, clinical, psychosocial, and preoperative outcome measures. The outcomes of interest were (i) knee extension and flexion range of motion, (ii) knee pain rated on a 5-point ordinal scale, and (iii) self-reported maximum walk time at 6 months post TKA. For each outcome, we fitted a multivariable proportional odds regression model with bootstrap internal validation. Results — At 6 months post TKA, around 5% to 20% of patients had a flexion contracture ³ 10°, range of motion < 90°, moderate to severe knee pain, or a maximum walk time £ 15 minutes. The model c-indices (the probabilities to correctly discriminate between 2 patients with different levels of follow-up TKA outcomes) when evaluating these patients were 0.71, 0.79, 0.65, and 0.76, respectively. Each postoperative outcome was strongly influenced by the same outcome measure obtained preoperatively (all p-values < 0.001). Additional statistically significant predictors were age, sex, race, education level, diabetes mellitus, preoperative use of gait aids, contralateral knee pain, and psychological distress (all p-values < 0.001). Interpretation — We have developed models to predict, for individual patients, their likely post-TKA levels of knee extension and flexion range of motion, knee pain, and walking limitations. After external validation, they can potentially be used preoperatively to identify at-risk patients and to help patients set more realistic expectations about surgical outcomes